LA JOLLA, Calif., Oct. 30 (UPI) - Against
         seemingly unbeatable odds, it turns out
         that new cells can sprout in the brain of
         an adult, even one in his 60s or 70s.

         Researchers make that remarkable
         assessment in Nature Medicine. While
         they say the unexpected findings that
         belie long-held beliefs about brain
         regeneration do hold promise of
         possible future treatments for brain
         diseases or damage, they caution they
         still do not know whether the new brain
         cells function normally - or what they
         do.

         "Like bubbles fizzing from champagne,
         it has long been assumed that our
         supply of brain cells steadily diminishes
         through our lives, never to be
         replenished," said senior study author
         Fred Gage of The Salk Institute for
         Biological Studies in La Jolla, Calif. "Our
         study, however, indicates new cells are
         born in human brains, even in mature
         individuals."

         Biologists have considered the
         replacement of dead brain cells highly
         unlikely at best. Neurons, the
         functional cells of the central nervous
         system, have long been thought to stop
         multiplying about the time youngsters
         lose their baby teeth and then to slowly
         die off throughout maturity.

         Dr. Ben Barres, a neurobiologist at
         Stanford University Medical Center,
         said the latest research carries
         "enormous potential."

         "If even a few cells with the power to
         regenerate could be harvested from
         stroke patients and patients with brain
         diseases, doctors might be able to
         induce them to grow in a laboratory
         dish and then graft them back into the
         diseased area, in the same way some
         burn victims can be treated with grafts
         of freshly grown skin cells," he said.

         The surprising results come from a
         study of terminal cancer patients as old
         as 72 who had undergone a diagnostic
         procedure that labels actively dividing
         cells. Following their death, the
         patients' brains were examined for
         presence of the diagnostic agent, said
         first author Peter Ericksson of the
         Sahlgrenska University Hospital in
         Goteborg, Sweden.

         "All of the patients showed evidence of
         recent cell division," Gage said. "It's
         interesting to note this was not a
         particularly young or healthy group of
         people, so new cell growth may usually
         be even more prominent than we
         observed."

         While new brain cell growth has been
         observed in adult marmoset monkeys,
         nothing of the kind has been detected
         in old world monkeys and apes, animals
         more closely linked to humans on the
         evolutionary family tree.

         The latest human studies show the new
         growth took place in the hippocampus,
         the part of the brain that has been
         linked with learning and memory.

         "At this point, it's premature to say the
         new cells are being used for learning
         and memory, but given their location in
         the brain, it seems reasonable to
         suggest they likely do," said study
         co-author Daniel Peterson.

         While scientists remain uncertain as to
         whether the new cells function
         properly, the finding casts an intriguing
         light on previous rodent studies that
         showed mice reared in stimulating
         environments generated new brain cells
         faster and performed better on learning
         and memory tests than their uninspired
         litter mates.

         "At the time those results were
         published, people would ask me if it
         meant they could literally increase their
         brain capacity by traveling or taking on
         new challenges, and I had to say we
         don't know," Gage said.

         "The current finding brings us an
         important step closer to thinking that
         we have more control over our own
         brain capacity than we ever thought
         possible previously."

         In terms of future treatments for brain
         disease and damage, the scientists say
         the big question remains of whether
         they can ever maneuver the new brain
         cells to undo the effects of stroke,
         injury and such neurological diseases as
         Parkinson's and Alzheimer's. Only
         further research will tell, they say.

         The research was funded by the
         National Institutes of Health, the
         National Institute of Neurological
         Disorders and Stroke, the Alzheimer's
         Association, the American Federation
         for Aging Research and numerous
         Swedish groups and societies.

         (Written by UPI Science Writer Lidia
         Wasowicz in San Francisco)